Merge remote-tracking branch 'upstream/dev' into integrate-upstream-dev-2026-08-15

# Conflicts:
#	src/helpers/ui/SH1106Display.cpp

src/MeshCore.h

@@ -72,6 +72,10 @@ public:
   virtual bool setLoRaFemLnaEnabled(bool enable) { return false; }
   virtual bool canControlLoRaFemLna() const { return false; }
   virtual bool isLoRaFemLnaEnabled() const { return false; }
+  // Software-selectable external FEM transmit gain. This is not a PA power switch.
+  virtual bool setLoRaFemPaGainEnabled(bool enable) { return false; }
+  virtual bool canControlLoRaFemPaGain() const { return false; }
+  virtual bool isLoRaFemPaGainEnabled() const { return false; }
 
   // Power management interface (boards with power management override these)
   virtual bool isExternalPowered() { return false; }